let s1 = Symbol()

let s2 = Symbol('hello')
let s3 = Symbol('hello')

// console.log(s2 == s3);

// let obj = {
//     abc: 123,
//     'hello':'world'
    
// }

// obj[abc] // 123
// obj['hello'] // 'world'

const PROP_NAME = Symbol()
const PROP_AGE = Symbol() 

let obj2 = {
    [PROP_NAME]:'冯总',
    title:'2222',
    [s2]:'1111',
    [s3]:'33'

}
obj2[PROP_AGE] = 18
console.log(obj2.keys());
console.log(Object.getOwnPropertySymbols(obj2));


const TYPE_AUDIO = 'AUDIO'
const TYPE_VIDEO